Roofing Terms Glossary
Reference This Handy List of Common Roofing Terms to Get a Better Understanding of the Many Components That Make up Your Roofing System
A
Algae
Rooftop fungus that can leave dark stains on roofing
Angled fasteners
Roofing nails and staples driven into decks at angles not parallel to the deck
APA
American Plywood Association - Tests and sets standards for all varieties of plywoods used in the U.S
Apron flashing
Metal flashing used at chimney fronts
ARMA
Asphalt Roofing Manufacturer’s Association - Organization of roofing manufacturers
Asphalt
A bituminous waterproofing agent used in various types of roofing materials
Asphalt concrete primer
Asphalt based primer used to prepare concrete and metal for asphalt sealant
Asphalt plastic cement
Asphalt based sealant material, meeting ASTM D4586 Type I or II. Used to seal and adhere roofing materials. Also called mastic, blackjack, roof tar, bull
ASTM
The American Society for Testing and Materials - Organization that sets standards for a wide variety of materials, including roofing
B
Back-surfacing
Granular material added to shingle’s back to assist in keeping separate during delivery and storage
Blistering
Blistering is bubbles or pimples in roofing materials - usually moisture related. In shingles, blisters are either moisture under the material or moisture trapped inside the material.
Blow-offs
When shingles are subjected to high winds, and are forced off a roof deck
Buckling
When a wrinkle or ripple affects shingles or their underlayments
C
Closed-cut valley
A shingle valley installation method where one roof plane’s shingles completely cover the other’s. - the top layer is cut to match the valley lines.
Cobra®
GAFMC’s respected brand name for ventilation products
Corrosion
When rust, rot or age negatively affect roofing metals
Counter-flashing
The metal or siding material that is installed over roof-top base flashing systems
Country Mansion® & Country Estates™
GAFMC’s limited lifetime warranty shingle
Crickets
A peaked water diverter installed behind chimneys and other large roof projections - effectively diverts water around projections
Cupping
When shingles are improperly installed over an existing roof or are over-exposed, they form a curl, or "cup."
D
Deck
The substrate over which roofing is applied - usually plywood, wood boards, or planks
Dormer
A raised roof extending out of a larger roof plane
Drip-edge
An installed lip that keeps shingles up off of the deck at edges, and extends shingles out over eaves and gutters, and prevents water from backing up under shingles
Dubl-Coverage® Mineral Guard
Roll roofing material with 19" selvage edge for double-coverage over roof deck
E
Eaves
The roof edge from the fascia to the structure’s outside wall - in general terms, the first three feet across a roof is termed the eave
End-laps
When installing rolled products in roofing, the area where a roll ends on a roof, and is overlapped by the next section of rolled material (underlayments, rolled roofing)
Exposure
The area on any roofing material that is left exposed to the elements
F
Fasteners
Nails or staples used in securing roofing to the deck
FHA
The Federal Housing Authority - Sets construction standards throughout the U.S.
Fiberglass mat
Fibers condensed into strong, resilient mats for use in roofing materials
Flange
Metal pan extending up or down a roof slope around flashing pieces - usually at chimneys and plumbing vents
Flashing
Materials used to waterproof a roof around any projections through the roof deck
Flashing cement
Sealant designed for use around flashing areas, typically thicker than plastic cement
G
Gable roof
Traditional roof style; two peaked roof planes meeting at a ridge line of equal size
GAFCant®
GAFMC cant strips for deflecting water away from flashing areas - typically used on low slope roofs
Golden Pledge®
GAFMC’s strongest limited warranty for shingles - America’s strongest steep-slope warranty
Grand Sequoia®
GAFMC shingle with wood shake appearance
Grand Slate™
GAFMC shingle with slate appearance
Granules
Crushed rock that is coated with a ceramic coating and fired, used as top surface on shingles
H
Hand-sealing
The method to assure sealing of shingles on very steep slopes, in high wind areas, and when installing in cold weather
High nailing
When shingles are nailed or fastened above the manufacturer’s specified nail location
Hip legs
The down-slope ridges on hip roofs
Hip roof
A roof with four roof planes coming together at a peak and four separate hip legs
I
Ice Dam
When a snow load melts on a roof and re-freezes at the eave areas - ice dams force water to "back-up" a roof and cause leakage
L
"L" flashing
Continuous metal flashing consisting of several feet of metal used at horizontal walls, bent to resemble an "L"
Laminated shingles
Shingles made from two separate pieces that are laminated together - GAFMC Timberline® Series, Country Mansion® and Grand Sequoia® Shingles - also called dimensional shingles and architectural shingles
Laps
The area where roll roofing or rolled underlayments overlap one another during application (see also side laps and end laps)
Low slopes
Roof pitches less than 4/12 are considered low sloped roofs - special installation practices must be used on roofs sloped 2/12-4/12
M
Mansard
A roof design with a nearly vertical roof plane that ties into a roof plane of less slope at its peak
Mats
The general term for the base material of shingles and certain rolled products
Modified bitumen
Rolled roofing membrane with polymer modified asphalt and either polyester or fiberglass reinforcement
Mortar
Mixture of sand, mortar, limestone and water used in bonding a chimney’s bricks together
N
Nail-guide-line
Painted line on laminated shingles, to aid in the proper placement of fasteners
Nail-pop
When a nail is not fully driven, it sits up off the roof deck
Nesting
Installing a second layer of shingles aligning courses with the original roof to avoid shingle cupping
NRCA
The National Roofing Contractors Association - Respected national organization of roofing contractors
O
Open valley
Valley installation using metal down the valley center
Organic mat
Material made from recycled wood pulp and paper
Organic Shingle
Shingles made from organic (paper) mats
OSB
Oriented Strand Board - A decking made from wood chips and lamination glues
Over-driven
The term used for fasteners driven through roofing material with too much force, breaking the material
Over-exposed
Installing shingle courses higher than their intended exposure
P
Pitch-ratio
Pitch-ratio of the rise of the roof to the span of the roof
Power vents
Electrically powered fans used to move air from attics and structures
Plastic cement
Asphalt based sealant - also called bull, mastic, tar, asphalt cement
Plumbing vents
Term used to describe plumbing pipes that project through a roof plane - also called vent stacks
Prevailing wind
The most common direction of wind for a particular region
Q
Quarter sized
Term for the size of hand sealant dabs, size of a U.S. 25¢ piece
R
Racking
Method of installing shingles in a straight up the roof manner
Rake edge
The vertical edge of gable style roof planes
Release film
The plastic sheet installed on the back of Weather Watch® and StormGuard® underlayments - Used for packaging and handling, remove before installation
Rigid vent
Hard plastic ridge vent material
Roof louvers
Rooftop rectangular shaped roof vents - also called box vents, mushroom vents, airhawks, soldier vents
Roof plane
A roofing area defined by having four separate edges - one side of a gable, hip or mansard roof
S
Sawteeth
The exposed section of double thickness on Timberline® Series shingles - shaped to imitate wood shake look on the roof
Self-sealant
Sealant installed on shingles - after installation, heat and sun will activate sealant to seal the shingles to each other
Selvage
The non exposed area on rolled roofing - area without granules, designed for nail placement and sealant
Shed roof
Roof design of a single roof plane - area does not tie into any other roofs
Shingle-Mate®
GAFMC’s shingle underlayment - breather type with fiberglass backing to reduce wrinkles and buckles
Side-laps
The area on rolled material where one roll overlaps the rolled material beneath it - also called selvage edge on rolled roofing
Side-walls
Where a vertical roof plane meets a vertical wall - the sides of dormers etc.
Soffit ventilation
Intake ventilation installed under the eaves, or at the roof edge
Smart Choice® Limited Warranty
GAFMC’s standard shingle limited warranty
Smart Choice® System Plus Limited Warranty
GAFMC’s next grade of enhanced warranty - extended coverage for owners
Starter strip
The first course of roofing installed - usually trimmed from main roof material
Steep slope roofing
Generally all slopes higher than 4/12 are considered steep slopes
Step-flashing
Metal flashing pieces installed at side-walls and chimneys for weather-proofing
StormGuard®
GAFMC waterproof underlayment - film surfaced rolled underlayment, 1.5 squares coverage per roll
T
Tab
The bottom portion of traditional shingle separated by the shingle cut-outs
Tear-off
Removal of existing roofing materials down to the roof deck
Telegraphing
When shingles reflect the uneven surface beneath them - shingles installed over buckled shingles may show some buckles
Timberline® Series
GAFMC’s trademark name for laminated wood shake style shingles
TIMBERTEX®
GAFMC enhanced Hip and Ridge Shingles
Transitions
When a roof plane ties into another roof plane that has a different pitch or slope
U
Under-driven
Term used to describe a fastener not fully driven flush to the shingles surface
Underlayments
Asphalt based rolled materials designed to be installed under main roofing material, to serve as added protection
V
Valleys
Area where two adjoining sloped roof planes intersect on a roof creating a "V" shaped depression
Vapor
Term used to describe moisture laden air
Ventilation
The term used in roofing for the passage of air from an enclosed space
W
Warm wall
The finished wall inside of a structure, used in roofing to determine how to install waterproof underlayments at eaves
Warranty
The written promise to the owner of roofing materials for material related problems
Waterproof underlayments
Modified bitumen based roofing underlayments - designed to seal to wood decks and waterproof critical leak areas
Weather Stopper® Integrated Roofing System™
GAFMC’s complete roofing system and components
Weather Watch®
GAFMC’s granule surfaced waterproof underlayment
Woven Valleys
The method of installing valleys by laying one shingle over the other up the valley center